AbstractThe Harvard Variable HV2576, as a red supergiant in the Large Magallanic Cloud, has a complex light variation, which is not explained well. The existing one-period non-linear pulsation model deviated clearly from its light curve. We tried to fit the light curve by a superposition of several harmonic pulsations. By using the PDM, PERIOD04 and SparSpec codes to analyze the light variation, two periods with 525 and 261 days are well established. Furthermore, the 261-day period is found to change according to the wavelet analysis. In addition, the noise obeying the 1/f law. Based on all these facts, we suggest that the light variation of HV2576 may be due to huge convection cells that interplay with oscillation or the third very long period.